How can I unpack UDP-packets(doubles) received from Simulink

Question

I am sending a UDP-packet in double data type to a RaspberryPi via Simulink. I want to decode the UDP-packet with the following code:

import struct
import socket

sock = socket.socket(socket.AF_INET,socket.SOCK_GRAM)

sock.bind(("",5002))

data,addr= sock.recvfrom(1024)
struct.unpack('d','data')
print data

and I receive the following error:

struct.error: unpack requires a string argument of length 8

thanks in advance for any help!

Answer 1

You have to check if you are sending big endian or little endian. you can add '<' for little endian and '>' for big endian data. Depends on how many variables you are receiving, the number of 'd' should increase as well. let's say you are receiving 2 struct.unpack('<'+'d','data')